361209 Ranunculus confervoides (Fr.) Fr.
Northern Iceland: Frequent
Northern Fennoscandia: Scattered
Kanin - Pechora: Scattered
Polar Ural - Novaya Zemlya: Scattered
Yamal - Gydan: Rare
Taimyr - Severnaya Zemlya: Rare
Anabar - Onenyo: Presence uncertain
Yana - Kolyma: Presence uncertain
West Chukotka: Rare
Western Alaska: Rare
Northern Alaska - Yukon: Scattered
Central Canada: Rare
Hudson Bay - Labrador: Scattered
Western Greenland: Frequent
Eastern Greenland: Scattered
Northern arctic Tundra: Rare
Mid Arctic Tundra: Scattered
Southern Arcti Tundra: Frequent
Shrub Tundra: Frequent
Bordering boreal or alpine areas: Frequent
- Fr., Summa Veg. Scand. 1: 139 (1845). - Batrachium confervoides Fr., Bot. Not. 1845: 121 (1845). Lectotype (UPS): Finland: Oulun Pohjanmaa, "Uleåborg" Oulu, leg. J.A. Ångström (Jonsell 1996: 7).
- Ranunculus aquatilis var. eradicatus Laest., Nova Acta Regiae Soc. Sci. Upsal. 11: 242 (1839). Described from northern Scandinavia. - Batrachium eradicatum (Laest.) Fr., Bot. Not. 1843: 114 (1843). - Ranunculus trichophyllus subsp. eradicatus (Laest.) C.D.K. Cook, Mitt. Bot. Staatssamml. München 6: 622 (1967).
- ?Ranunculus lutulentus E.P. Perrier & Songeon in Billot, Annot. Fl. France Allemagne: 181 (1859). Type: France: Savoie, près Conflans, leg. E. Perrier de la Bâttle. - Ranunculus trichophyllus subsp. lutulentus (E.P. Perrier & Songeon) Vierh., Abh. K.K. Zool.-Bot. Ges. Wien 16: 109 (1935). - Batrachium trichophyllum subsp. lutulentum (E.P. Perrier & Songeon) Janch., Cat. Fl. Austriac. 2: 196 (1958).
32 (4x). - Europe (N, C), Far East (N), Canada, Greenland. - Several reports.
A Yukon Territory report of 2n = 32 by Mulligan and Porsild (1969b for R. aquatilis var. subrigidus) may belong to R. confervoides.
Not included: Reports of numbers different from 2n = 32 probably belong to other species or hybrids, e.g., 2n = 24 (3x) from northern Siberia (Zhukova et al. 1977) and 2n = 48 (6x) from Chukotka (Zhukova 1982).
Geography: Amphi-Atlantic - European - Asian (N) - amphi-Beringian: ICE NOR RUS SIB RFE ALA CAN GRL.
Notes: Nearly all current Fennoscandian field botanists accept Ranunculus confervoides as species and refute - as theoretical considerations based on badly preserved or incomplete herbarium specimens - the Continental European attempts to reduce it to a race of R. aquatilis or R. trichophyllus. They also refute the North American attempts to describe it as a variety of R. aquatilis or to include it in a race of R. circinatus. Delimitation is sometimes more difficult among R. peltatus, R. aquatilis, R. trichophyllus, and R. circinatus than between R. confervoides and the others. Ranunculus confervoides has its distinct range even if it sometimes is found together with R. trichophyllus and R. subrigidus. Intermediates (aborting hybrids) towards the others are rarely observed, whereas they are common between the others. The reason for this may be that R. confervoides is very small-flowered, often flowers even when submerged, and may be largely self-pollinating. In the last maps of Hultén (Hultén and Fries 1986), this is the only species of sect. Batrachium which really reaches the Arctic, but see R. subrigidus below.
The names "confervoides" and "eradicatus" are based on northern Fennoscandian plants and refer to the same taxon. Whether the name "lutulentus", based on a plant from the French Alps, refers to this taxon should be checked by a renewed inspection of types, not influenced by the idea that this taxon is the same as R. aquatilis or R. trichophyllus.
Aiken and Elven: Two species are present in the Canadian Arctic Archipelago: R. confervoides and R. subrigidus, as opposed to the simple picture given by Hultén and Fries (1986) and Whittemore (1997). A revision of the material suggests that R. confervoides is restricted to Baffin Island and replaced by R. subrigidus elsewhere in the islands. A subsequent revision of material from Alaska and mainland Canada (ALA, CAN; Elven in 2009) supports R. confervoides and R. subrigidus as consistently different but as sometimes co-occurring in the arctic and near arctic parts. In the west, R. confervoides reaches across from Asia to Alaska and perhaps the Yukon Territory but not east of the Mackenzie.
Tzvelev and Elven: The name Batrachium eradicatum (Laest.) Fr. 1843 has priority before B. confervoides Fr. 1845. The priority species name in Ranunculus is R. confervoides due to homonymy.
- Ranunculus [3612,genus]